「欧州最大の捕食恐竜」　英化石ハンターが発見

【パリＡＦＰ＝時事】英国南部沖のワイト島で見つかった化石が、欧州の捕食陸上動物としては史上最大とみられるスピノサウルス科恐竜のものであることが分かったとする論文が９日、英サウサンプトン大学の研究チームにより、科学誌「ＰｅｅｒＪ」に発表された。（写真は化石が発見されたスピノサウルス科恐竜の想像図。英サウサンプトン大学提供）
　見つかった骨の大半は、同島沿岸での恐竜化石探しに生涯をささげ、英国有数の化石ハンターとして知られていた故ニック・チェイス氏によって発見された。
　研究チームは、見つかった少数の骨からこの恐竜を特定。新種として正式に命名することを目指している。研究を主導した博士課程の学生クリス・バーカー氏は「全長１０メートルを超える巨大生物で、一部（の骨）の大きさからみるに、欧州で見つかった捕食性恐竜としてはおそらく史上最大のもの」としている。
　生息時期は、約１億２５００万年前の白亜紀前期と推定。バーカー氏によると、英国で見つかったスピノサウルス科恐竜としては、有名なバリオニクスよりも２００万～３００万年遅く、最も新しい時代のものだという。
　スピノサウルス科の恐竜は２本足で歩き、頭部はティラノサウルス・レックス（Ｔ・レックス）のような箱形ではなく、ワニのように細長かった。この特徴から、陸上だけでなく水中でも狩りを行っていたという説が有力だ。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2022/06/10-13:11）

A giant crocodile-faced dinosaur, discovered on the Isle of Wight by one of Britain's best fossil hunters, was probably the largest predator ever to stalk Europe, scientists said on Thursday.
Most of the bones of the two-legged spinosaurid were found by the late local collector Nick Chase, who dedicated his life to combing the beaches of the island on England's southern coast for dinosaur remains.
Researchers at the University of Southampton then used the few bones available to identify what they have called the White Rock spinosaurid, they said in a study published in the journal PeerJ.
This was a huge animal, exceeding 10 metres (33 feet) in length and judging from some of the dimensions, probably represents the largest predatory dinosaur ever found in Europe, said Chris Barker, a PhD student who led the study.
While admitting it would be better to have more bones, Barker told AFP the numbers don't lie -- it is bigger than the biggest known specimen previously found in Europe.
Thomas Richard Holtz, a vertebrate paleontologist from the University of Maryland not involved in study, agreed that the new find does seem to be larger than a huge predator whose fossilised remains were discovered in Portugal.
Matt Lamanna, a dinosaur palaeontologist at Carnegie Museum of Natural History in the US, praised the excellent, thorough study of the specimen given the lack of bones, but said it was difficult to compare sizes.
For example, he said the biggest known spinosaurid, the Spinosaurus, was likely the longest such dinosaur but it probably wasn't as heavy as the Tyrannosaurus rex or the Giganotosaurus -- the latter of which is about to become super-famous thanks to the new 'Jurassic World' movie.
- Why the long face? -
The White Rock spinosaurid -- which the researchers hope to formally name as a new species -- is from the Early Cretaceous period and is estimated to be around 125 million years old.
Barker said that makes it the youngest spinosaurid found in Britain, two or three million years younger than the well-known Baryonyx.
Spinosaurids are known for their elongated heads. Rather than having the boxy skull of a Tyrannosaurus rex, their faces look more like that of a crocodile.
A leading theory to explain this trait is that they hunted in water as well as on land.
They're kind of like storks and herons, wading in and snatching fish from the surface, Barker said.
The White Rock spinosaurid was discovered in a coastal lagoon environment where few dinosaur fossils are normally found.
It helps start to paint a picture of what animals were living in the time, which is a very poorly known part of English palaeontological heritage, Barker added.
The team had already identified two new spinosaurid species on the Isle of Wight, including the Ceratosuchops inferodios -- dubbed the hell heron.
This new animal bolsters our previous argument -- published last year -- that spinosaurid dinosaurs originated and diversified in western Europe before becoming more widespread, study co-author Darren Naish said.
- Collector's 'uncanny ability' -
The palaeontologists paid tribute to Chase, who always donated whatever bones he found to museums.
Most of these amazing fossils were found by Nick Chase, one of Britain's most skilled dinosaur hunters, who sadly died just before the Covid epidemic, said study co-author Jeremy Lockwood, a PhD student at the University of Portsmouth.
Barker said Chase's uncanny ability to find bones showed that it's not just professional palaeontologists who are making impacts in the discipline.
The discovery highlights the fact that collectors have a big role to play in modern palaeontology and their generosity helps move science forwards, he added.
And if there any aspiring fossil hunters hoping to pick up where Chase left off, the palaeontologists would welcome more White Rock spinosaurid bones.
We hope that a passerby might pick up some bits and donate them, Barker said.